The study states no conflict of interest, but found it a bit ironic that the next link on HN was https://news.ycombinator.com/item?id=46682534 , stating that "Nearly a third of social media research has undisclosed ties to industry"
There are a lot of "foundations" funding their research. I don't have the patience to go searching through them to see if they may be causes of conflict of interest first, second or third hand. I just assume there's a conflict unless other research from reputable sources backs it up.